This is a proposal for a Program Project Grant for the investigation of the molecular basis of viral transformation. The Program itself will be a part of the Oncology Division which is described in more detail below, and includes projects on herpes, EB, papova and parvo viruses, as well as certain aspects of oncorna viruses. A major part of the proposed research is concerned with the organization and expression of those genes of DNA viruses that are involved in transformation. The Program Project Grant would give formal recognition and support to a group of investigators who are already involved in research collaborations and teaching related to Tumor Virology. The scientific interests and backgrounds of the members of this group represent the range of disciplines from biological to molecular aspects of virology.